Cost effective energy storage, suitable for storing energy from new as well as traditional energy sources and delivering the energy when needed, is clearly a “missing link” for more efficient exploitation of new and existing energy sources.
Storage of energy allows for better match between when energy is produced and when it needs to be used; in short this means the ability to “time shift” energy delivery. This is particularly important for facilitating higher penetration of renewable energy. Typically there is no delivery of wind energy when the wind does not blow and there is no solar energy available when the sun has gone down. Beyond this, traditional power units such as coal fired and nuclear power plants operate most efficiently with a constant power production whereas the market demands typically varies strongly through a 24 hour day cycle. Moreover, by placing storage near to where power is used implies that the main electric grid may be utilized more efficiently and limitations by bottlenecks in transmission can be overcome. Large scale and “grid scale” energy storage is clearly a key component in an environmentally friendly, efficient future power system making the most out of renewable and other energy sources.
In patent publication WO 2012/169900 A1, a Thermal Energy Storage (TES) is described, having beneficial properties over prior art storages. More specifically, a practical and cost effective solution is provided for a thermal storage using solid-state material as the main storage medium, allowing for storage of energy in the form of high temperature heat, which means thermal energy at sufficiently steam turbine-generator set or equivalent means.
In international patent application PCT/NO2013/050120, it is described how thermal energy storages like those according to the teaching of WO 2012/169900 A1 are beneficial in order to simplify and increase efficiency of energy plants of various types, such as for concentrated solar power plants and nuclear power plants.
Despite the significant steps forward, provided by the technology described above, there is still a need for further improvements. The effect/cost ratio is always in demand for improvement, as well as the versatility and flexibility of the thermal energy storage with respect to sources of energy. Further, providing better reliability of delivery from renewable energy sources such as sun and wind is clearly another goal. The objective of the present invention is to meet growing needs and demands with new technology.